scholarly journals Relative growth, sexual maturity and handedness in the ghost shrimp Callichirus major (Decapoda: Callianassidae) from the southwestern Atlantic

2019 ◽  
Vol 83 (2) ◽  
pp. 167 ◽  
Author(s):  
Juliana Priscila Piva Rio ◽  
Patricio Hernáez ◽  
Marcelo Antonio Amaro Pinheiro
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Adult Males ◽  
Allometric Growth ◽  
Growth Phases ◽  
Relative Growth ◽  
Ghost Shrimp ◽  
Living Organisms ◽  
Main Growth

Biometric studies provide valuable information about changes associated with the growth and sexual maturity of living organisms. We analysed sexual dimorphism, allometric growth, sexual maturity and handedness in the ghost shrimp Callichirus major at Gonzaga beach, Brazil, where the catches of this species have been prohibited since 1992. To this end, a total of 544 individuals of C. major were collected during 12 months of sampling. Males were significantly smaller than females, denoting sexual dimorphism with respect to body size. The analysis of allometric growth between chelar carpus length and carapace length (CL) revealed a positive allometric relationship in juveniles of both sexes and adult males, but a negative allometry in adult females. Overall, our results showed the existence of two main growth phases related to sexual maturity, with a similar transition point for males (15.0 mm CL) and females (16.0 mm CL). Heterochely and homochely were registered in shrimp from both sexes, but in males heterochely occurred to a higher degree and was predominant (86.9%), whereas in females homochely was slightly more frequent (59.3%). The consequences of sexual dimorphism in terms of body size and chelipeds in the mating system of C. major are discussed in this study.

Sexual dimorphism in the Neotropical lizard, Tropidurus torquatus (Squamata, Tropiduridae)

2005 ◽  
Vol 26 (2) ◽  
pp. 127-137 ◽  
Author(s):  
Helga Wiederhecker ◽  
Adriana Pinto ◽  
Guarino Colli
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Body Shape ◽  
Patch Size ◽  
Adult Males ◽  
Lizard Species ◽  
Central Brazil ◽  
Adult Females ◽  
Males And Females

AbstractWe describe the sexual dimorphism in coloration, body shape, and body size in Tropidurus torquatus, a widely distributed lizard species in central Brazil. Adult males have colored patches varying from yellow to yellow-and-black, and black on the abdomen, ventral aspect of the thighs, and pre-cloacal flap. Adult females lack ventral colored patches. During ontogeny, there is a gradual darkening of the patches, but no modification either in patch size or color is associated with the reproductive cycle. Adult males have wider heads and thinner bodies than females of the same body size. Males and females grow at the same rate prior to sexual maturity, but males take longer to reach sexual maturity, maturing at a larger body size than females.

The manifestation and significance of sexual dimorphism in anguid lizards: a case study of Barisia monticola

1989 ◽  
Vol 67 (1) ◽  
pp. 68-72 ◽  
Author(s):  
James L. Vial ◽  
James R. Stewart
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Reproductive Behavior ◽  
Reproductive Potential ◽  
Head Size ◽  
Adult Males ◽  
Allometric Growth ◽  
Natural And Sexual Selection ◽  
Dimorphic Expression

The dimorphic expression of body size, body – head size relationships, and chromatic characters among anguid lizards is reviewed. These characteristics are quantitatively examined in a population of Barisia monticola. No sexual differences are found in body size. Head size is positively correlated with body size; however, allometric growth rates in head size are significantly greater in adult males than in females or juveniles. Adult males also differ significantly in eight of nine chromatic characters, the most pronounced being the presence of light dorsal scale markings. These differences are explored in the context of both natural and sexual selection. We hypothesize that the absence of dimorphism in overall body size is the result of natural selection operating to maximize female reproductive potential. In contrast, we predict that dimorphism expressed in body – head size relationships and dichromatism are consequences of sexual selection relating to agonistic and reproductive behavior of males.

Sexual Dimorphism in the Lobster (Homarus americanus)

1944 ◽  
Vol 6c (3) ◽  
pp. 228-232 ◽  
Author(s):  
Wilfred Templeman
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Homarus Americanus ◽  
Total Length

In relation to total length of body, the longer carapace and the accessory copulatory appendage of the male and the longer fourth swimmeret of the female are seen in the immature but develop further during and after sexual maturity. The small sternal spines and long second swimmeret of the female and the wider carapace of the male develop with sexual maturity and become more pronounced with increase in body size.

scholarly journals Relative growth of freshwater prawn Macrobrachium brasiliense (Decapoda, Palaemonidae) and its implications for reproduction

2019 ◽  
Vol 109 ◽  
Author(s):  
Caio dos Santos Nogueira ◽  
Marcela Silvano de Oliveira ◽  
Giuliano Buzá Jacobucci ◽  
Ariádine Cristine de Almeida
Keyword(s):  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Freshwater Prawn ◽  
Relative Growth ◽  
Guarding Behavior ◽  
Males And Females ◽  
One Year ◽  
Almost All

ABSTRACT The main objective of this study was to estimate the morphological sexual maturity of Macrobrachium brasiliense (Heller, 1862) and to analyze the relative growth of the species. During one year of sampling, from July 2012 to June 2013, 199 specimens were collected in a stream located in a Cerrado biome, in the Triângulo Mineiro region, state of Minas Gerais. Once identified and sexed, the length of the carapace, the length of the segments of the chelipeds (ischium, merus, carpus, propodus and dactyl) and width of the pleura were measured (mm). The maximum and mean sizes of the carapace length measured 20.5 mm (Mean: 9.6 ± 4.2 mm) and 20.1 mm (Mean: 7.7 ± 3.4 mm) for males and females, respectively. The propodus length for males, and the pleura width for females, were used for the classification of the specimens into juvenile and adult, using K-means analysis and discriminant analysis. The relative growth of the species was also evaluated through covariance analysis for all structures (ANCOVA, α = 0.05). In females, the growth of most structures occurred equally between juveniles and adults, with the exception of the merus and pleura structures. On the other hand, the growth of almost all structures of males differed between juveniles and adults. Only the carpus and the pleura growth were similar. We also estimated the size at onset of morphological sexual maturity at 8.64 mm CL for males (CL50% r = 1.71) and 8.03 mm CL for females (CL50% r = 0.07). Our results contribute to the understanding of some important questions related to the reproductive biology of M. brasiliense. We noted that males grow differently from females and become the largest individuals in the population, resulting in a sexual dimorphism. Such sexual dimorphism might promote the development of the temporary mating guarding behavior, a reproductive strategy very important for caridean shrimps.

scholarly journals Comparative biology of the crab Goniopsis cruentata: geographic variation of body size, sexual maturity, and allometric growth

2015 ◽  
Vol 69 (4) ◽  
pp. 335-342 ◽  
Author(s):  
José Jonathas Pereira Rodrigues de Lira ◽  
Tereza Cristina dos Santos Calado ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva
Keyword(s):  
Body Size ◽  
Geographic Variation ◽  
Sexual Maturity ◽  
Comparative Biology ◽  
Allometric Growth

scholarly journals Size at sexual maturity of female crabs Sesarma rectum Randall (Crustacea, Brachyura) and ontogenetic variations in the abdomen relative growth

2005 ◽  
Vol 22 (2) ◽  
pp. 433-437 ◽  
Author(s):  
Maria H. de A. Leme
Keyword(s):  
Sexual Maturity ◽  
Carapace Width ◽  
Analysis Of Covariance ◽  
Northern Coast ◽  
Growth Phases ◽  
Differential Growth ◽  
Relative Growth ◽  
Gonadal Maturity ◽  
Body Sizes ◽  
Size At Sexual Maturity

The aim of the present study was to ascertain the size at sexual maturity in females of the crab Sesarma rectum Randall, 1840 by comparing gonadal maturity to morphologic maturity (using abdomen-width data). The relative growth of the abdomen was analysed for all growth phases (for each 3-mm carapace width size class), and the slopes of the separate allometric relationships were compared through analysis of covariance (ANCOVA) from log e-transformed data to detect changes in the level of allometry during ontogeny. The physiological size at maturity (gonadal criteria) was determined through a logistic curve, indicating the size at which 50% of females presented mature gonads (M50 = 17.4 mm CW). The highest allometric levels occurred in growth phases 2 and 3 (body sizes ranging from 15 to 21 mm CW), indicating faster growth of the abdomen during those phases. Phases 1 (< 15 mm CW) and 4 and 5 (size classes above 21 mm CW) showed isometric growth. In the study area, a mangrove on the northern coast of the state of São Paulo, Brazil, individuals of S. rectum began to reach sexual maturity from 15 mm CW onward, when the slopes of the relationship of abdomen width to carapace width became positively allometric, indicating a differential growth rate. A gradual decrease in the slope, tending to isometry, occurred during ontogeny, as the animals became larger (older).

Relative growth, life-history phases, and sexual maturity of American lobster (Homarus americanus)

2010 ◽  
Vol 88 (4) ◽  
pp. 347-358 ◽  
Author(s):  
Kim Émond ◽  
Bernard Sainte-Marie ◽  
Louise Gendron
Keyword(s):  
Life History ◽  
Sexual Maturity ◽  
Body Part ◽  
Homarus Americanus ◽  
American Lobster ◽  
Body Parts ◽  
Growth Phases ◽  
Major Life ◽  
Relative Growth ◽  
Cephalothorax Length

Previous studies of relative growth in crustaceans have focused primarily on body parts representing sexual characters for the purpose of determining size at onset of sexual maturity. We have revisited the relative growth of abdomen and crusher claw in American lobster ( Homarus americanus H. Milne Edwards, 1837) in a general life-history perspective using a broad spectrum of lobster sizes (6–160 mm cephalothorax length (CL)). Growth phases were recognized by inflections in scatterplots of a body-part measurement against CL. The abdomen is characterized by three growth phases in the male and female, whereas the crusher claw has at least three growth phases in the male and at least two in the female. Additionally, we explored relative growth of gonopod and vas deferens for males of 35–150 mm CL. Both organs exhibit a synchronous change from strong to weak positive growth allometry. The growth phases can be associated with major life-history events including the transition from a cryptic to an overt lifestyle and the onset of physiological, functional, and morphometric maturity. The onset of morphometric maturation inferred from relative growth of abdomen and crusher claw precedes functional maturity in females and follows it in males.

scholarly journals Life history of Tendaguru sauropods as inferred from long bone histology

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 103-112 ◽  
Author(s):  
P. M. Sander
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Upper Jurassic ◽  
Bone Histology ◽  
Long Bone ◽  
Large Mammals ◽  
Growth Series ◽  
History Of

Abstract. Sauropod dinosaurs present exceptional challenges in understanding their biology because of their exceptional body size. One of these, life history, can be inferred from the histology of their bones. For this purpose, the diverse sauropod assemblage of the Upper Jurassic Tendaguru beds was sampled with a new coring method which provided unprecented access to and insights into sauropod bone histology. Growth series of humeri and femora as well as long growth records from single bones suggest that all four sauropod taxa are characterized by continued growth after sexual maturity but that growth was determinate. Fibrolamellär bone is dominant in the samples, indicating that the bones of the Tendaguru sauropods grew at rates comparable to those of modern large mammals. The growth pattern of these sauropods thus combines typically reptilian traits with typically mammalian traits. In the details of their bone histology, the Tendaguru sauropod taxa show considerable variation which reflects life history. In addition, Barosaurus exhibits probable sexual dimorphism in bone histology. Das Verständnis der Biologie der sauropoden Dinosaurier wird durch ihre enorme Körpergröße außerordentlich erschwert. Allerdings kann ein Aspekt, die Lebensgeschichte, anhand der Histologie ihrer Knochen untersucht werden. Zu diesem Zweck wurde die diverse Sauropoden-Vergesellschaftung der oberjurassischen Tendaguru-Schichten beprobt, und zwar mit einer neuartigen Kernbohrmethode, die einen herausragenden Zugang und Einblick in die Knochenhistologie der Sauropoden ermöglichte. Wachstumsserien von Humeri und Femora sowie umfassende Überlieferungen des Wachstums von Individuen anhand einzelner Knochen machen es wahrscheinlich, daß alle vier Sauropoden-Taxa der Tendaguru-Schichten durch ein auch nach der Geschlechtsreife anhaltendes Wachstum gekennzeichnet waren. Allerdings ging das Wachstum nicht bis zum Tode des Tieres weiter, sondern kam bei einer etwas variablen Maximalgröße zum Stillstand. Fibrolamellärer Knochen ist der vorherrschende Knochentyp in den Proben, was anzeigt, daß die Tendaguru-Sauropoden mit für Säugetieren typische Raten wuchsen. Die Tendaguru-Sauropoden kombinerten also ein für Reptilien typisches Muster des Wachstums, nämlich nach der Geschlechtsreife anhaltendes Wachstum, mit für Säuger typischen Raten des Wachstums. Die verschiedenen Sauropoden-Taxa zeigen erstaunliche Unterschiede in den Details ihrer Knochenhistologie, die Unterschiede in der Lebensgeschichte belegen. Bei Barosaurus scheint außerdem ein Geschlechtsdimorphismus in der Histologie der Langknochen vorzukommen. doi:1002/mmng.1999.4860020107

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